/ˈkaʊntdaʊn ||; ˈkaυntˌdaυn/noun [C] the act of saying numbers backwards to zero just before sth important happens 倒数；倒数计时: the countdown to the lift-off of a rocket 火箭发射前的倒数计时 (figurative 比喻) The countdown to this summer's Olympic Games has started. 今年夏天的奥林匹克运动会已进入倒数计时。